Tappet



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L7M M, M. Willi-,COX

TAPPET Filed Sept. 19, 1919 [NI/ENTOR ATTORNEY Patented et, d, i9.,

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P A T MERRILL M. WILCOX, F SAGINAW, MICHIGAN.

TAPPET.

Application led September 19, 1919. Serial No. 324,959.

To all whom z't may concern.

Be it known that l, MERRILL M. WILcoX, a citizen of the United States,residing at Saginaw, in the county of Saginaw and e State of Michigan,4have invented certain new and useful Improvements in Tappets; and ll dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled and use the same. y

'llhis invention relates to valve-actuating tappets for internalcombustion engines, and pertains more particularly to certain novelfeatures of construction embodied in a multiple-piece valve tappet as anew article of manufacture, whereby ll am enabled toA produce anexceptionally light, but strong,

tappet, with a head of very hard metal such as case-hardened steel tocontact with the engine cam. A tappet of this kind also usually has aninternal plug in the end opposite the head to receive the bolt or otheradjustable device that contacts with the stem of the valve. Preferredarrangements of such tappet plugs are shown and described and claimed inmy co-pending applications constituting divisions of this presentapplication.

The arrangement lof parts in my improved tappet construction is suchthat they can be easily, quickly and accurately assembled and theindividual parts can be manufactured at small cost and by automaticmachines of standard construction, insuring uniformity of size and shapeand weight.

With the foregoing and certain other objects in view, which will appearlater in the specification, my invention comprises the devices describedand claimed, and the equiva lents thereof.

My invention is illustrated in the accompanying drawings, in which lFig. 1, is a central longitudinal section of a tappet, in workingrelation to an engine cam, the end plug being removed.

Fig. 2 is a side view of a preferred forni of tappet head.

Figs. 3 and i are similar views showing modified forms of the tappethead.

As is clearly shown in the drawings, the 'tappet consists of a body 1,which is preferably formed by boring a solid bar of metal to form athin-walled tube; or the body may be formed of sheet metal rolled to theform of a tube, or b drawing and pressing froma. dat sheet o met-al, orby using a short piece of tubing of proper diameter and thickness.

Secured to the body 1 'at one end is a head member 2, formed of aseparate piece of metal, heat-treated and hardened. 'llhe head 2 may be,and in practice is preferably formed with a laterally projecting flange3, the face of which is preferably ground to contact with the cam e ofthe engine, as shown in Fig. 1.

An elongated axially projecting cylindrical shank 5 is formed on thehead 2 and is accurately fitted to and preferably received in theaperture of the body 1, to which it is secured by spot welding, as in Fig. 1; or by being threaded and screwed into place, as shown in F i 3;or by forming the shank with depressions 6, as indicated in Fig. 4, andcorrespondingly swaging or depressing the metal of the apertured bodythereinto. The foregoing are practica-l and well-known means of securingcylindrical members in shells, and may be employed in carrying out myinvention. ll prefer in practice, however, to weld the shank 5 in thebore or aperture of body 1, as shown in lFi 1.

By the means above escribed, I have produced a tappet of light weightand great strength. The parts are adapted to be easily and economicallymanufactured by automatic machinery and can be rapidly and accuratelyassem led either by semi-automatic machinery, or by hand.

rlhe elongated shank 2, formed integral with the flange 3 provides astrong and rigid structure admirably suited to withstand the shocks ofrapidly repeated contacts with the cam and the shank itself affordsample transverse strength and anchorage for the lower end of shell 1.This will be understood from the fact that the cam during the first halfof the lift of the tappet causes a strong sidewise thrust against thetappet,

forcing the tappet laterally against the guidewap, in which the tappetslides up and down. f

point where it enters the guideway has a the shell of the tappet at thev thin wall, such wall will buckle when the The elongated shank 5 ofapplicants 110 hardened head is always in the guideway during theoperation of the tappet and consequently the side thrust is withstood bythat part of the shell which is reinforced by the long shank, avoidingthe danger of distorting or making the tappet stick.

Having thus described my invention, what I claim and desire to secure byLetters Pat ent is:

1. A tappet for internal combustion engines comprising a hollow tubularbody, an independent cam-contacting head of'hardened material having anelongated axially pro'ecting shank integral with said head, said shankreceived in and fixed to an end of said body.

2. As an article of manufacture,'a tappet for internal combustionengines comprising a hollow tubular body of substantially uniformexternal diameter throughout its length, an independent cam-Contactinhead of hardened material and an elongate cylindrical shank inte 'ralwith said head, said shank received within said tubular body and fixedto one end thereof.

3. InA a multiple piece tappet includin an apertured boiy, acam-Contactin head comprising a har ened face and an e ongated axiallyprojecting shank integral with said face, said shank received in theapertune of said body and fixed thereto.

4. A tappet includin a tubular body, a cam-contacting head o hardenedmaterial,

said head formed with an elongated cylindrical shank, said shankreceived within said body and fixed to one end thereof.

5. A tappet including a tubular body, a camcontacting head of hardenedmaterial, saidhead formed with an elongated cylindrical shank, saidshank received within said body and welded thereto.

In testimony whereof, I aix my signature.

MERRILL M. WILCOX.

